Biogena Vitamin D 2000 DUO is a quality preparation with a high content of vitamin D3 (50 µg corresponds to 2000 international units per capsule) and linseed oil to improve vitamin D absorption, as well as the plant substance lutein. The fat-soluble vitamin D contributes to the maintenance of normal immune functions, muscle functions and a normal calcium level in the blood. It supports the absorption and utilization of calcium and phosphorus and plays a role in the maintenance of normal bones.